Hartman attended Radford High School in Radford, Virginia, where he made the school's varsity team and served as backup goalkeeper in 1989. As a sophomore he started for a young Radford High Team that went 1-12, where Hartman once gave up six goals in a half. That Radford High team won the Region IV Title in 1992 over Blacksburg High School and lost in the state semi-finals. RHS would have likely contended for the state title in 1992; however, between his sophomore and junior year at Radford High School, Hartman moved with his family to the Palos Verdes in California, where he enrolled in Palos Verdes High School, playing on the junior varsity squad for the 1990-1991 season. Before his senior year, Palos Verdes High School merged with Rolling Hills High School and Miraleste High School to form Palos Verdes Peninsula High School. As a senior, Hartman played on the Peninsula High School varsity squad, though he only started a few of the games early in the season. Hartman also played on a club team known as the San Pedro FC Santos, headed by Pat Nave of San Pedro, California.

Known as having a strong work ethic, Hartman often woke up early in the morning to practice in the nearby city of Long Beach. After graduating from high school in the Spring of 1992, Hartman went on to play college soccer at Cal State Dominguez Hills and UCLA. He began his college career at Dominguez Hills, playing there in 1992 and 1993, before transferring to UCLA, where he played in 1995 and 1996, redshirting in 1994.

Hartman was drafted 29th overall in the 1997 MLS College Draft by Los Angeles Galaxy. He played very little his rookie year, as he was stuck behind renowned Mexican keeper Jorge Campos. After the season, Hartman, or "El Gato" (dubbed by La Opinion reporter),was selected third overall by Chicago Fire in the expansion draft; the Galaxy quickly reacquired him, however, trading Campos and Chris Armas to the Fire in exchange for Hartman and Danny Pena. With Campos in Chicago, Hartman seized the starting job, starting 28 games for the team kept it until his departure from the team, except for a brief period in 2001 when Matt Reis briefly took his job. He was named MLS Goalkeeper of the Year in 1999 following an especially good season. Hartman helped the Galaxy win the U.S. Open Cup in 2001 and 2005 and the MLS Cup in 2002 and 2005. After ten years with the Galaxy, Hartman was traded to Kansas City Wizards following the 2006 season.

On March 28, 2009, Hartman broke the all-time MLS saves record of 1,136 stops previously held by Tony Meola during a Wizards game against Colorado Rapids.[1]

Kevin left Kansas City when he failed to agree to a new contract extension with the club.[2] Hartman's rights were traded to FC Dallas in return for a conditional second round 2012 MLS SuperDraft pick.[3]

On September 16, 2010, in a match against New York Red Bulls, Kevin was injured by Red Bulls striker Thierry Henry, who wanted to kick the ball to celebrate a goal. Henry kicked the ball and the follow through kicked Hartman's foot, causing him an injury.[4]

Following the 201 MLS season, Hartman's contract was not renewed by FC Dallas.[9] Hartman entered the 2012 MLS Re-Entry Draft in December 2012 and became a free agent after going undrafted in both rounds of the draft. On March 21, 2013, Hartman joined the New York Red Bulls as a free agent saying "to play and also have the opportunity to get into a little bit more of the coaching side of things."[10] Hartman announced his retirement from professional soccer on November 21, 2013.[11]

Despite his success in MLS, Hartman saw little time with the United States national team, making only six international appearances. He received his first cap September 8, 1999 in a match against Jamaica, while his last international appearance came on February 10, 2006 in a friendly against Japan.

LA RIOT SQUAD Founder: After a loss in 2001, Kevin Hartman approached a few and offered a deal. Put together a group of about 100 fans to stand, sing, & support the team and they’d get a beer keg.[citation needed]